#include"stdio.h"
#include"math.h"
#include"libsec4.h"



static double alpha, G,Ms,Mm;
void jump(double x, double y[MMAX], double dy[MMAX])
{
    double v = sqrt(y[2] * y[2] + y[3] * y[3]);
    double r=sqrt(y[0]*y[0] + y[1] * y[1]);
    double a = G*Ms / (r*r*r) * (1 + alpha / (r*r));

    dy[0] = y[2];
    dy[1] = y[3];
    dy[2] = a * y[0];
    dy[3] = a * y[1];
}